• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.281-286
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• 2010

The objective of this study was to analyze the microbial populations in the raw ingredients of kimchi and their changes during an automated commercial manufacturing process. High population numbers of total aerobic bacteria, lactic acid bacteria, Leuconostoc sp., and yeast were detected in garlic, ginger, red pepper powder and this result revealed that these ingredients were the major source of microbials in kimchi. Additionally, during the salting process of Chinese cabbage, rapid microbial growth was observed and the consecutive washing process was determined to be ineffective, lowering the microbial count by only one log reduction. Yeast was also detected in various ingredients. These results strongly suggest that, in order to lower the microbial population numbers in kimchi, the side-ingredients and salting process should be subjected to the appropriate sanitization or sterilization processes at the HACCP level. Beside, treatment of salted Chinese cabbage with sodium hypochlorite solutions after the salting step is recommended. To inhibit yeast growth, appropriate chemical treatment and approval of additive uses to control microbials should be considered. These experimental results and suggestions will be used to improve the kimchi manufacturing process in factories.

• Journal of the Korean Wood Science and Technology
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• v.34 no.6
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• pp.61-71
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• 2006

This study was carried out to investigate chemotaxonomical correlation an d the chemical constituents of domestic Quercus sp. leaves. The leaves of Q. mongolica, Q. aliena, Q. serrata, Q. acutissima, Q. dentata and Q. variabilis were collected in the experimental forest of Kangwon National University. The combined extracts were successively fractionated with n -hexane, methylene chloride and ethyl acetate using a separation funnel. A portion of the ethyl acetate and $H_2O$ soluble materials of each species were chromatographed on a Sephadex LH-20 column using various aqueous MeOH and EtOH-hexane as washing solvents. Spectrometric analysis such as NMR and MS, including TLC, were performed to characterize the structures of the isolated compounds. Gallic acid, (+)-catechin, (-)-epicatechin, (+)-gallocatechin, kaempferol, astragalin, astragalin-6"-O-gallate, isoquercitrin, isoquercitrin-6"-O-gallate and myricetin were isolated from Q. mongolic a leaves. Gallic acid, kaempferol and quercetin were characterized from Q. acutissima leaves. Gallic acid, (+)-catechin, (-)-epicatechin, (+)-gallocatechin, (-)-epigallocatechin, kaempferol, quercetin, guajaverin and tamarixin were identified from Q. dentata leaves. Gallic acid, (+)-catechin, (-)-epicatechin, kaempferol, quercitrin, isoquercitrin and myricetin were purified from Q. serrata leaves. Gallic acid, (+)-catechin, astragalin, astragalin-6"-O-gallate and isoquercitrin were isolated from Q. variabilis leaves. Gallic acid was isolated from all the leaves and could be a taxonomic index on Quercus spp..

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.253-261
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• 2013

The purpose of this study was to investigate the aflatoxin $B_1$ binding of lactic acid bacteria (LAB) isolated from Korean traditional soybean paste and to evaluate the effect of incubation conditions and physico-chemical factors on the binding ability of LAB to this mutagen. The amount of aflatoxin $B_1$ bound by Enterococcus faecium DJ22, Lactobacillus fermentum DJ35, Lactobacillus rhamnosus DJ42, and Lactobacillus pentosus DJ47 was strain specific with the percent bound ranging from 19.3% to 52.1%. However, Enterococcus faecalis DJ14, Lactobacillus panis DJ29, and Pediococcus halophilus DJ50 strains did not exhibit any of the binding ability to aflatoxin $B_1$. For most strains, the binding ability was significantly affected by the environmental conditions such as the aflatoxin $B_1$ level, incubation time and temperature, and the initial cell count of LAB. The stability of the aflatoxin $B_1$-bacteria complexes was significantly more unstable after washing. In addition, the binding stability between viable and nonviable cells was not statistically significant. Treatment with heating, acidic pH, ${\alpha}$-amylase, protease, lysozyme, or sodium metaperiodate caused a significant (P<0.05) decrease in aflatoxin $B_1$ binding for the tested strains, suggesting that carbohydrates or proteins in the cell walls may be involved in aflatoxin $B_1$ binding ability. Since the aflatoxin $B_1$ binding of LAB was significantly reduced (P<0.05) by the pretreatment of the urea, the binding force observed in this study may have resulted from hydrophobic interaction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04a
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• pp.41-41
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• 2008

In general, polyimides (PIs) are used in alignment layers in liquid crystal displays (LCDs). The rubbing alignment technique has been widely used to align the LC molecules on the PI layer. Although this method is suitable for mass production of LCDs because of its simple process and high productivity, it has certain limitations. A rubbed PI surface includes debris left by the cloth, and the generation of electrostatic charges during the rubbing induces local defects, streaks, and a grating-like wavy surface due to nonuniform microgrooves that degrade the display resolution of computer displays and digital television. Additional washing and drying to remove the debris, and overwriting for multi-domain formation to improve the electro-optical characteristics such as the wide viewing angle, reduce the cost-effectiveness of the process. Therefore, an alternative to non-rubbing techniques without changing the LC alignment layer (i.e, PI) is proposed. The surface of LC alignment layers as a function of the ion beam (IE) energy was modified. Various pretilt angles were created on the IB-irradiated PI surfaces. After IB irradiation, the Ar ions did not change the morphology of the PI surface, indicating that the pretilt angle was not due to microgrooves. To verify the compositional behavior for the LC alignment, the chemical bonding states of the ill-irradiated PI surfaces were analyzed in detail by XPS. The chemical structure analysis showed that ability of LCs to align was due to the preferential orientation of the carbon network, which was caused by the breaking of C=O double bonds in the imide ring, parallel to the incident 18 direction. The potential of non-rubbing technology for fabricating display devices was further conformed by achieving the superior electro-optical characteristics, compared to rubbed PI.

• Journal of the Korean Wood Science and Technology
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• v.38 no.4
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• pp.359-374
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• 2010

This study was carried out to investigate the chemotaxonomical correlation and chemical constituents of domestic Quercus spp. barks. The barks of Q. mongolica, Q. aliena, Q. serrata, Q. acutissima, Q. dentata, and Q. variabilis were collected in the experimental forest of Kangwon National University. The combined extracts were successively fractionated with n-hexane, methylene chloride and ethyl acetate using a separation funnel. A portion of the ethyl acetate and H2O soluble materials of each species were chromatographed on a Sephadex LH-20 column using various aqueous MeOH and EtOH-hexane as washing solvents. Spectrometric analysis such as NMR and MS, including TLC, were performed to characterize the structures of the isolated compounds. Ellagic acid (0.03 g), (+)-catechin (4.59 g), taxifolin (3.35 g), and glucodistylin (20.52 g) were isolated from Q. mongolica bark. Gallic acid (0.18 g), (+)-catechin (8.52 g), (+)-gallocatechin (0.09 g), taxifolin (0.54 g), and glucodistylin (3.28 g) were characterized from Q. acutissima bark. Gallic acid (0.38 g), ellagic acid (0.11 g), (+)-catechin (2.01 g), (+)-gallocatechin (0.12 g), and glucodistylin (0.39 g) were identified from Q. dentata bark. Ellagic acid (1.51 g), (+)-catechin (21.91 g), and glucodistylin (3.91 g) were purified from Q. aliena bark. Ellagic acid (0.84 g), (+)-catechin (0.82 g), taxifolin (4.02 g), and glucodistylin (21.50) were isolated from Q. serrata bark. Gallic acid (0.24 g), caffeic acid (0.05 g), (+)-catechin (0.32 g), and glucodistylin (0.65 g) were purified from Q. variabilis bark. (+)-Catechin and glucodistylin were isolated from all the barks. Glucodistylin can be a taxonomic index on Quercus spp.

• Journal of the Korean Chemical Society
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• v.39 no.3
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• pp.204-212
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• 1995

The graphite furnace atomic absorption spectrophotometric determination of trace lead in water samples was studied using matrix modifiers. In order to modify the sample matrix, the type and optimum amount of the modifier were investigated with a given concentration of Pb solution. In fact, if the matrix is not modified, lead has low ashing and atomization temperatures as to give a low absorbance with bad reproducibility because of its volatility. Therefore, optimum modifiers should be used to stabilize the atomization. In this work, the ashing and atomization temperatures were raised from 400 and $1800^{\circ}C$, to 1,000 and $2000^{\circ}C$, by the addition of palladium to 50 ng/mL lead solution as a modifier. The concentration of palladium was 5.0 ${\mu}g/mL$ in the modified solution. Furthermore, if 1.5 ${\mu}g/mL$ of aluminum was mixed with the palladium modifier as an auxiliary modifier, the ashing temperature could be increased $150^{\circ}C$ additionally. With such a treatment, the sensitivity was improved more than 5 times of the solution unmodified and the reproducible results of less than 5% RSD were obtained in the samples of university's waste water and pipe-washing tap water. It could be concluded that this procedure was quantitative in the determination of trace lead from the recoveries of more than 88% obtained in the samples in which a given amount of lead was spiked.

• International Journal of Advanced Culture Technology
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• v.5 no.3
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• pp.24-34
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• 2017

Nail art is a kind of nail painting or decoration that adds to the beauty. Throughout making nail art, the worker was on a dusty operation with the smoothing of chemicals and nails. People working at nail shops not only use a variety of chemicals, but also experience a lot of fine powder during the process of nail trimmings. While drying the chemical adhesive, the workers often complain of eye, nose and throat discomfort. In addition, the acrylic brush is characterized by a lot of smell when washed with washing solution. Also nail art workers directly influence the worker's breathing through the work done by placing the guest's hands in a work space called a nail table. Chemical ingredients used in nail art procedures include acetone, ethyl acetic acid, toluene, butyl acetic acid, glue, and top coating of nail varnishes. Prolonged inhalation of these substances may cause dizziness, vomiting, as well as impaired respiratory system. The purpose of this study is to investigate the respiratory symptoms of nail shop workers who are likely to be affected by work in nail shop and to find out which factors have the greatest influence if they have respiratory symptoms. Therefore this study is to provide basic data on the health management system of people engaged in nail shop and to develop health education program. For this study, the data collection was collected on July 7, 2017 for the nail shop workers attending the nail art trend seminar held in Gwangju, in Korea. The data were all 236. However, except for the poor data, 208 data were used for the final analysis. The questionnaire consisted of 30 in general questions, questions about self-efficacy in 24 questions. elf-efficacy measuring tool developed by A.Y, Kim, I. Y, Park(2001). The self-efficacy questionnaire consists of 24 items and is self-reported 7-point Likert scale. The reliability of this tool was cronbach alpha = .934.The collected data were analyzed using spss 18.0. Information of Research participant performed frequency analysis. To examine the effects of personal characteristics on self-efficacy, $X^2$ analysis was conducted. And also $X^2$ analysis was conducted to analyze the coughing symptom appearance according to individual and environmental factors. A hierarchical regression analysis was used to determine which of the personal and environmental factors influenced cough symptoms.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.730-738
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• 1992

Filtration characteristics according to membrane materials were studied In the ultrafiltration of anaerobic digestion broth as a post treatment method. A series of resistances for different membranes were quantitatively assessed on the basis of the resistance-in-series model. Flux behavior observed with the digestion broth was irrelevant to initial water permeabilities of each membrane. The fluoro polymer membrane showed the most significant improvement of flux with increase of cross-flow velocity, which suggests that the cake layer formed on this membrane is more weakly attached to the membrane surface than those on the other membranes. Flux reduction during longtime running was attrib-used to the polarization layer resistance ($R_p$) as well as the fouling layer resistance($R_f$). Continuous increase of $R_p$ may reflect the variation in the characteristics of cake layers, which could result from size, shape, and structure changes due to lysis and growth of biomass. Hydrophilic cellulosic membrane had a much lower fouling tendency than hydrophobic polysulfone membrane. The depressurization method induced a small increase in flux of $5-10L/m^2/h$. During washing and cleaning, filtrability of each membrane was rapidly recovered within 15 minutes until a stationary value was reached.

• Membrane Journal
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• v.27 no.2
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• pp.199-204
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• 2017

In this study, a study was carried out for the separation of metal ions in lignin extract discharged from the pulp process. alumina powders were mixed with DMAc (N, N-dimethylacetamide) solvent and PESf (Polyethersulfone) polymer, PVP (polyvinylpyrrolidone) dispersant was added and slip casting method was used to prepare the membrane. The membrane was measured for pore size through a CFP (Capillary Flow Porometer) device and the surface and cross-section of the membrane were observed through a FE-SEM (Field Emission Scanning Electron Microscope). The flux was calculated by measuring the filtered weight per hour using a separation experiment device. Pore size measurements were performed under increasing pressure from 0 psi to 30 psi. The pore size of the membrane was $0.4{\mu}m$ and the flux decreased from the initial flux value of $6.36kg{\cdot}m^{-2}{\cdot}h^{-1}$ to $1.98kg{\cdot}m^{-2}{\cdot}h^{-1}$ due to the fouling of the membrane. After the permeation experiment, membrane contaminants were removed by simple washing. Separation experiments showed that Na contained in the initial lignin extract was reduced by 69%, Fe was removed by 87%, K by 95%, Ca by 93% and Mg by 96%.

• Journal of Sensor Science and Technology
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• v.11 no.2
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• pp.102-110
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• 2002

The chemical and mechanical characteristics of a new surface modifier, dichlorodimethysilane (DDMS, $(CH_3)_3SiCl_2$), for stiction-free polysilicon surfaces are reported. The main strategy is to replace the conventional monoalkyltrichlorosilane(MTS, $RSiCl_3$) such as octadecyltrichlorosilane (ODTS) or 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS) with dialkyldichlorosilane (DDS, $R_2SiCl_2$) with twit short chains, especially DDMS. DDMS, with shorter chains in aprotic media, rapidly deposits on the chemically oxidized polysilicon surface at room temperature and successfully prevents long cantilevers of 3 mm in length from in-use as well as release stiction. DDMS-modified polysilicon surfaces exhibit satisfactory hydrophobicity, long term stability and thermal stability, which are comparable to those of FDTS. DDMS as an alternative to FDTS and ODTS provides a few valuable advantages; ease in handling and long-term storage in solution, low temperature-dependence and low cost. In addition to the new modifier molecule, the simplified process of direct release right after washing the modified surface with isooctane was proposed to cut the processing time.